The latest version of the Senate health care bill creates an exemption that allows insurance companies to offer cheap plans that don't include basic protections required under current law—including mandatory coverage of pre-existing conditions.

Basically, as long as health insurance companies provide at least one "compliant" plan, they can also sell "non-compliant" plans that are designed to appeal to people who are young, healthy, and don't want to pay high premiums for holistic health care. For example, a compliant plan would feature mandates that require coverage for things like mental health treatment, and the premiums for those plans would be significantly higher than non-compliant plans, which would cover only the medical essentials such as annual doctor visits. Part of the reason non-compliant plans will be so cheap is that they won't have to cover pre-existing conditions, a foundational tenet of Obamacare.

These are 29 pre-existing conditions that insurers could opt out of covering through non-compliant plans, according to the Kaiser Family Foundation.

1. AIDS/HIV
2. Lupus
3. Alcohol abuse/ Drug abuse with recent treatment
4. Mental disorders (severe, e.g. bipolar, eating disorder)
5. Alzheimer’s/dementia
6. Multiple sclerosis
7. Arthritis (rheumatoid), fibromyalgia, other inflammatory joint disease
8. Muscular dystrophy
9. Cancer within some period of time (e.g. 10 years, often other than basal skin cancer)
10. Obesity, severe
11. Cerebral palsy
12. Organ transplant
13. Congestive heart failure
14. Paraplegia
15. Coronary artery/heart disease, bypass surgery
16. Paralysis Crohn’s disease/ ulcerative colitis
17. Parkinson’s disease
18. Chronic obstructive pulmonary disease (COPD)/emphysema
19. Pending surgery or hospitalization
20. Diabetes mellitus
21. Pneumocystic pneumonia
22. Epilepsy
23. Pregnancy or expectant parent
24. Hemophilia
25. Sleep apnea
26. Hepatitis (Hep C)
27. Stroke
28. Kidney disease, renal failure
29. Transsexualism

Even young, healthy people might want to think twice about buying into non-compliant plans.

The catch of non-compliant plans is that if you enroll in one and later develop a condition that your insurance doesn't cover (see above), not only will you face steep deductibles but you could also be labeled as having a pre-existing condition if you want to enroll in a more comprehensive plan. That means any insurer could charge you more or deny you coverage for becoming ill while you were on a non-compliant plan.

And because non-compliant plans don't count as "continuous coverage," you'd be subject to a six-month waiting period before you're able to enroll in a new plan—a penalty for uninsured individuals that's built into the Senate health bill.

For context, almost 40 percent of Americans will develop some form of cancer in their lifetime, according to the National Cancer Institute. Good lifestyle habits can reduce your risk of developing certain conditions, but statistically, there's always a chance that you could find yourself in need of better coverage. And if you run into that problem on a non-compliant plan, it'll cost you.